Some history first. I previously had a friends 230F in my possession to uncork and tune. I used his bike as a reference to test my modded 230F against. My 230F has Fox shock, 150R forks, BBR 67mm piston, ST2.0 cam, head work by Terry, OE Outlaw exhaust, procom box, 13/47 gears. After much back to back testing between these two bikes, I was really disappointed in engine performance of my modded bike. Mine was faster, but only slightly. Suspension, no comparison between stock of course. So I ordered a OKO PWK and installed it using some rubber adapters from Home Depot. After a few needle and jet changes, I found a good setting that works very well almost everywhere, only a small flat spot at about 3/8 throttle. We had a ride yesterday and I was able to compare my NEW bike to my friends uncorked 230F as before. When I unloaded my bike and cranked it, he was amazed at how different it sounded and did not believe I had only added the PWK. I am happy to report that my modded bike performs as I was expecting, no comparison between the two bikes. It runs fantastic from bottom to top with a strong off idle pull and it really screams from 1/2 to WFO. I didn't think a 2 valve bike could work so well. i think the learning is these bikes respond very very well to the basic uncorking, the most bang for the buck since it is free. Even after adding 10cc's, more compression, a better cam, better exhaust, head porting, my bike was only slightly better than the free uncorking I did on my friends bike. But, after the PWK, WOW!